If you would like to convert an existing Pitlock locking skewer to another size such as switching from a wider rear hub to a front hub, you'll need a skewer with the correct length.
Please note that if you intend to convert a wheel skewer to a seatpost skewer, the pressure washer (the part that contacts your frame) will also need to be replaced because the seatpost skewer uses a convex pressure washer. For this reason, you'll notice that the price is slightly higher.